Polyacrylate, pressure sensitive adhesive, pressure sensitive tape, soft magnetic shield

With the continuous development of wireless charging in many fields such as smart phones, smart wearables, smart homes, and new energy vehicles, the 100-billion-level market has caused social related enterprises to increase investment. However, there are many problems in wireless charging, which also make the industry headache. High charging efficiency, slow temperature rise, ultra-thin and so on are the development direction of the entire industry. As one of the key components of wireless charging technology, magnetic materials play a role in increasing the induction magnetic field and shielding coil interference in wireless charging equipment, so wireless charging equipment has high requirements on the function, product size and reliability of magnetic materials.

However, the traditional ferrite materials in wireless charging have serious heating problems, slow charging, charging power is small, has been unable to meet the demand for high-power charging. The use of nanocrystalline soft magnetic material as a shield has many advantages, the permeability of nanocrystalline, charging efficiency is higher than ferrite, nanocrystalline material strip is a fragile thin layer, thickness between 18μm to 30μm, in the process of adhesion magnetic fragmentation into discontinuous fragmentation, and can be soft and ultra-thin. At the same time communication equipment such as mobile phones to thin development, and small space.

That is, the tape should be ultra-thin, but also meet the viscosity stability of the temperature rise during wireless charging; The adhesive tape is required to have high bonding strength and good coating effect on nanocrystalline fragments when making nanocrystalline magnetic conductive pieces.

The existing electromagnetic shield technology 1 discloses a composite magnetic body: it is formed by rolling the flat soft magnetic metal powder and the magnetic powder of the insulating film formed on the surface of the metal powder, and the adhesive tape is no longer required between the two layers.

The existing electromagnetic shield sheet technology 2: discloses a single/multilayer magnetic sheet for wireless charging: a layer of magnetic wafer, the wafer is evenly distributed with a plurality of cracks, and the plurality of cracks will divide the wafer into a plurality of fragmentation units; A plurality of cracks are filled with an insulating medium so that the crack on both sides of the fragmentation units insulation each other.

The double-sided adhesive adhesive is adhered to one side of the magnetic sheet, and the other side of the magnetic sheet is formed with a protective film composed of the insulating medium. More specifically, the amorphous or nanocrystalline strip after heat treatment is bonded, cracked, impregnated, dried and cured to form the above structure.